Measurements and Instrumentations LAB VIVA Questions :-
1. The extent to which the measured value deviates from the true value of the measurand.
2. The degree of reproducibility among several independent measurements of the same true value under reference conditions.
3. The ability of a measuring device to reproduce output readings when the same measurand value is applied to it repeatedly under the same environmental conditions and in the same direction.
4. A measure of the probability that a measuring device will continue to perform within specified limits of error over a specified length of time under specified conditions.
5. The magnitude of discernable or detectable output changes as the measurand is continuously varied over the range.
6. The time required for the output of measuring device to reach a specified percentage of its final value as a result of a step change of measurand.
7. The algebraic difference between the max-imum and minimum limits of the range.
8. The ability of a measuring device to retain its repeatability and other characteristics throughout its specified operating life and storage life.
9. The measurand values over which a measuring device is intended to measure, specified by upper or lower limits.
10. The time required for the output of a measuring device to rise from 10% to 90% of its final value.
11. The amount of output measured beyond the final steady output value in response to a step change in the measurand.
12. The maximum deviation of any calibration point, obtained for either increasing or decreasing input, from the best fit straight line having overall minimum deviation.
13. The maximum difference in output for the same measurand value within the range of a measuring device, one obtained by increasing from zero and other by decreasing from a higher value of the measurand.
14. The algebraic difference between the indicated or observed value and the true value of the measurand.
15. The random changes in output under constant measurand and normal operating conditions.
16. A test during which standard values of measurand are applied to the measuring device and the corresponding output readings are compared with the standard values.
17. The time during which a device or system is insensitive, after receiving a stimulus, to any other impulse or stimulus.
18. The utilization of supplemental device, materials, or processes to minimize known sources or error.
19. A calibration during which the measurement varies with time in a specified manner and the. output is recorded as a function of time.
20. Characteristics of a measuring device which relate to its response to variations of the measurand with time.
21. The impedance presented to the excitation source, measured across the excitation ter-minals of a measuring device.
22. The impedance across the output terminals of a measuring device presented by it to the associated external circuitry.
23. The physical quantity, property, or condition that is to be measured.
24. The maximum magnitude of measurand that can be applied to a measuring device without causing a change in performance beyond specified tolerance.
25. A change in output over a specified period of time at specified ambient conditions with input held constant.
26. The period of time, starting with the ap-plication of power to the measuring device, required to assure that it will perform within specified tolerance.
27. A device which provides a usable output in response to a specified measurand.
28. The smallest change in the measurand that produces a detectable change in the transducer output.
29. The time required for the output of a transducer to rise to 63.2% of its final value as a result of a step change in the measurand.
30. An excitation and amplification system for use with transducers.
31. The output response of a system or network to a unit step at the input.
32. A characteristic of a system describing the relationship between specified points when system variables are not changing.
33. A process or rule for deriving from a given mathematical entity a corresponding entity.
34. A mathematical expression relating the output of a system or device to its input, usually written as a function of the Laplace complex variable (s).
35. The output of a system after sudden ap-plication of a change at the input and before steady-state conditions have become established.
36. A quantity whose value is represented by a single continuous variable.
37. A quantity that can only have discrete values.
38. A general term to describe information.
39. The study of the simultaneous variation of two or more variable quantities.
40. A tendency of a system to break into un-wanted oscillation.
41. The conditions of the medium (like temperature, pressure, humidity, vibration, radiation, etc.) surrounding the measuring device.
42. A line midway between two parallel straight-lines close together and enclosing all output versus measurand values, on a calibration curve.
43. A mechanical element of generally cylindrical shape with cylindrical walls having deep convolutions.
44. A pressure sensing element consisting of a twisted or curved tube of non-circular cross section which tends to get straightened on the application of internal pressure.
45. The range of values over which a measured variable can change without affecting the output.
46. A sensing element consisting of a thin flexible circular plate which can be actuated by a pressure differential applied across the plate.
47. The rating applicable to a specified operation for a specified uninterrupted length of time.
48. A pressure sensing element consisting of two corrugated metallic diaphragms joined along their circumference.
49. The rating applicable to a specified operation over a stated number of time intervals of specified duration.
50. The complex impedance presented to the output terminals of a transducer by the associated circuitry or load.
51. The part of the transducer which responds directly to the measurand.
52. The ratio of the change in transducer output to a corresponding change in the value of the measurand.
53. A calibration performed by application of the measurand to the transducer at discrete amplitude intervals.
54. The impedance presented to the transducer’s excitation terminals by the excitation source;
55. The response of a transducer (to a step) fast change in the measurand.
56. A point maintained close to ground potential by negative feedback, although not directly connected to the ground.
57. A mathematical relationship between the input and the output, expressed as a ratio of two polynomials.
58. Observation, measurement and mathematical operation performed with time considered as the principal variable.
59. Transmission to a distance of measured quantities, usually by radio or telephony, with suitably coded modulation.
60. A property of a system, whereby the system returns to a state of equilibrium after disturbance.
61. A characteristic of some systems which prevents rapid changes or excessive instability.
62. Variations in a unified pattern which represent relevant pieces of information.
63. The modification of a carrier waveform in response to the information to be carried.
64. A physical variable whose specification re-quires two points in space.
65. A device which, when actuated by one form of energy, is capable of converting it to another form of energy.
66. The error observed when the instrument is under the reference condition.
67. Difference obtained by subtracting the true value of a quantity from the observed value.
68. The ratio of the absolute error to the true value.
69. Errors caused by such effects as friction, spring hysteresis, noise, and other phenomena.
70. Random errors indicated when repeated measurements of the same quantity result in differing values.
71. Relatively constant errors occurring due to such effects as sensitivity drift, zero effect, known non-linearities, etc.
72. Unwanted disturbances, superimposed on low level input signals due to noise, hum, line pickup, ripple, switching transients and line transients.
73. Deviation observed in the instrument output with time from the initial value, whenall other measurement conditions remain same; the deviation may be caused by a change in component values due to variation in ambient conditions or due to ageing.
74. Percentage of the departure from the linear value, i.e. maximum deviation of the output curve from the best-fit straight line during any calibration cycle.
75. The maximum error in calibration at any point on the scale to the absolute measurement or theoretical straight line.
76. Linearity referred to a straight line between the theoretical end points.
77. A special case of theoretical slope linearity for which the theoretical end points are 0% and 100% of the full-scale output.
78. Linearity referred to a straight line between the experimental end points.
79. Linearity referred to the best straight line (a line midway between the closest possible two parallel straight lines) enclosing all the output values obtained during one calibration cycle.
80. Linearity referred the straight line for which the sum of the squares of the residuals (deviations of output readings from their corresponding points on the best-fit straight line) are minimised.
81. The deviation of the mean value of repeated measurements from the best fit line.
82. The range of the measurand variable for which an instrument is designed to measure linearly.
83. Probability that a system will perform its assigned functions for a specific period of time under given conditions.
84. Instruments which can be characterized by one parameter (time constant).
85. Instruments which are characterized by two parameters (natural frequency, and damping ratio).
86. An extremely accurate and absolute unit certified by the national standards institution to be within allowable tolerances.
87. The reference calibrated standards, designed and constructed from the primary (absolute) standards.
88. The normal standards needed by the individual establishments and laboratories, having one order of accuracy lower than the secondary standards.
89. Comparison of specific values of the input and output of an instrument with a cor-responding reference standard.
90. Transducers- operating under energy conver-sion principles and self-generating devices, without any external energizing source.
91. Transducers operating under energy con-trolling principles which require secondary electrical energy from an external source.
92. Ability to withstand overloads, with safety stops for overload protection.
93. A system in which the output is exactly of the same form as that of the input, but it occurs after a transmission lag.
94. Effect which occurs when a transverse magnetic field is applied to a current-carrying conductor.
95. That part of the expression of the result of a measurement which states the range of values within which the true value is estimated to lie.
96. The smallest increment of the measurand which can be detected with certainty by the instrument.
97. The largest change cf the measurand to which the instrument does not respond, and is produced by friction, backlash, or hysteresis in the instrument.
98. The maximum distance or angle through which any part of a mechanical system may be moved in one direction without applying appreciable force or motion to the next part in a mechanical sequence.
99. A measure of the ability of the instrument to restore to zero reading after the measurand has returned to zero, and other variations (like temperature, pressure, humidity, vibration, etc.) have been removed.
100. Force or torque necessary just to initiate motion from rest.
101. The friction force or torque which opposes motion of the output.
102. Friction which varies as a function of the velocity of a mechanism, and produces damping and affects the response of the out-put due to introduction of lag in motion.
103. Errors subject to irregular or chance causes and can be treated by statistical methods.
104. Errors arising due to use of an inadequate measurement method or caused by un-favourable environmental condition, or by original calibration error, or by human error.
105. The ratio of standard deviation and square root of the number of observations.
106. A way of removing unwanted interference and noise.
107. A semiconductor whose temperature coef-ficient at room temperature (25°C) is about-4%/°C, normally negative and at least ten times as sensitive as the platinum resistance thermometer.
108. Production of an e.m.f. by light incident upon a p-n semiconductor junction.
109. A crystalline or ceramic material, in which a potential difference appears across opposite faces, as a result of dimensional changes due to the application of a mechanical force.
110. Conversion of the measurand into a voltage ratio by a change in the position of a movable wiper on a resistance element across which excitation is applied.
111. Conversion of a measurand into a change in resistance or conductivity by a change in the magnitude of illumination incident upon the material.
112. Conversion of the measurand into a change in voltage generated when a junction between dissimilar materials is illuminated.
113. Conversion of the measurand into a change of emission of electrons due to a change in the incidence of photons on a photocathode.
114. Conversion of the measurand into a change in electrostatic charge or voltage generated by certain materials when mechanically stressed.
115. Conversion of the measurand into a change in the resistance of a conductor or semiconductor by a change in the mechanical stress applied to it.
116. The change in the resistance of a conductor or semiconductor due to the application of a magnetic field.
117. The change in dimension of a ferromagnetic object when the object is placed in a magnetic field.
118. The device which generates an output signal proportional to the applied force or weight.
119. The quantity of matter in a body.
120. The complex ratio of force to velocity during simple harmonic motion.
121. The generation of charges in certain crystals when unequally heated or cooled.
122. A theoretical slope for which the theoretical end points are 0% and 100% of both measurand and output.
123. The generation of electric charge by friction between surfaces.
124. The part of the transducer in which the output information originates.
125. The sensitivity of a transducer to a specified value of inputs applied in an axis orthogonal to the designed sensitive axis.
126. The step transfer process by which the transducer calibration can be related to the reference standards.
127. Conversion of the measurand into a change in e.m.f. generated by a temperature difference between the junctions of two selected dissimilar metals.
128. The axis along which the input measurand is applied or mounted.
129. Sum of the static pressure and the impact pressure in a fluid flow.
130. A short non-periodic or transient excitation of a mechanical system.
131. A transducer or a device whose characteristics are precisely known relative to a primary standard.
132. The unwanted component (typically or broad frequency spectrum) on the output of a measuring device.
133. A vector unit that specifies the time rate of change of an acceleration.
134. The specified minimum length of time over which the specified continuous or intermittent rating of a measuring device applies without changing its performance beyond specified tolerances.
135. The specified minimum length of time over which a measuring device can be exposed to a specified storage condition, without changing its performance beyond specified tolerances.
136. The specified minimum number of full range excursions or specified partial range excursions over which a measuring device will operate as specified without changing its performance beyond specified tolerances.
137. The DC resistance measured between specified insulated portions of a measuring device when a specified DC voltage is applied.
138. A measuring device whose output is a time integral function of the measurand.
139. The distortion in the output of a measuring device, in the form of harmonic other than the fundamental component.
140. A motion whose instantaneous amplitude varies sinusoidally with time.
141. Conversion of the measurand into a change in ionization current through a gas between two electrodes.
142. The range of frequencies over which the faithful reproduction of the measurand is obtained.
143. The ratio of the Laplace transform of the output quantity to the Laplace transform of the input quantity, when all initial conditions are zero.
144. Minimum value of input below which no output can be detected.
145. The quantity represented by the slope of the input-output curve if the ordinates are represented in actual units.
146. Change in the value of the measured variable due to extraction of some energy to a measuring instrument with an input signal source.
147. For transmission of maximum power from a device, the impedance of external load should match its internal impedance.
148. A device that measures, and generates an opposing effect to maintain zero deflection.
149. A device whose output is an enlarged reproduction of the essential features of the input wave and which draws power from a source other than the input signal.
150. The device which reduces the amplitude of the signal without causing appreciable distortions in it.
151. The ratio of difference between measured value and true value to the true value of the measurand.
152. Signal varying cyclically with time or repeating itself after a constant interval.
153. Signal varying non-cyclically with time, i.e. the signal is of a definite duration and becomes zero after a certain period of time.
154. Signal varying randomly with time, with no definite period and amplitude.
155. The output response of an instrument to various types of dynamic input signals ob-tained by solving its governing equation relating output and input.
156. Variation of output signal against frequency-
157. An instrument having no dynamic error and no time lag of measurement.
158. Technique of analysis of the measured data for evaluating errors and deviations.
159. Time required by a measurement system to begin to respond to a change in the measurand.
160. The largest change of input quantity for which there is no output of the instrument.
161. The magnitude of the impedance of element connected across the signal source.
162. Equivalent impedance as seen by the load connected across a device.
163. Reduction in magnitude, amplitude, or in-tensity of a physical quantity.
164. A pictorial and functional representation of a system.
165. Section of a frequency spectrum within which component frequencies of a signal can pass.
166. The ability of a device to reduce the effect of a common signal at both input points.
167. A signal applied simultaneously to both inputs of a differential amplifier.
168. A system that controls a variable by using error-sensing through a closed loop.
169. A characteristic of some systems which prevents rapid changes or excessive instability.
170. A logarithmic ratio of powers (P2/P1) i.e. 10 log10 (P2/P1).
171. The signal applied between the two un-grounded terminals in a balanced three-terminal system.
172. A device which discriminates between fre-quencies.
173. Observation, measurement and mathematical operations performed with frequency con-sidered as the principal variable.
174. The process of sharing a single channel with more than one data input.
175. A high-gain d.c. amplifier used with an external feedback path.
176. The introduction of unwanted voltages and currents into signal leads.
177. The ratio of the effective value of an alter-nating quantity to its average value over a half-period.
178. A graphical representation of the effect on the solutions of a system characteristic equation as a system parameter is varied.
179. A spectrum which characterises the frequency content of a random signal.
180. The process of separating the wanted in-formation from the noise component.
181. The frequency of free oscillations in a system.
182. A point maintained close to ground potential by negative feedback, although not directly connected to ground.
183. The theory which allows analysis and synthesisation of engineering systems with less effort, greater accuracy and more understanding.
6. response time
10. rise time
11. over shoot
17. dead time
19. dynamic calibration
20. dynamic characteristics
21. input impedance
22. output impedance
25. zero shift
26. warm-up period
29. time constant
30. signal conditioning
31. step response
32. static characteristic
34. transfer function
35. transient response
36. analog signal
37. digital signal
41. ambient condition
42. best fit straight line
44. Bourdon tube
45. dead band
47. continuous rating
49. intermittent rating
50. lead impedance
51. sensing element
53. static calibration
54. source impedance
55. Transient response
56. virtual ground
57. transfer function
58. time domain
66. intrinsic error
67. absolute error
68. relative error
69. random errors
71. systematic errors
72. interference errors
73. zero drift
75. absolute linearity
76. theoretical slope linearity
77. terminal linearity
78. end point linearity
79. independent linearity
80. least square linearity
86. primary standard
87. secondary standard
88. working standards
90. active transducers
91. passive transducers
93. dead-time element
99. zero stability
100. striction (static friction)
101. dynamic coulomb friction
102. viscous friction
103. random errors
104. systematic errors
105. SEOM (standard error of the mean)
106. signal filtering
108. photovoltaic effect
110. potentiometric transduction
111. photoconductive transduction
112. photovoltaic transduction
113. photoemissive transduction
114. piezo electric transduction
115. piezovoltaic transduction
116. magneto resistive effect
118. load cell
120. mechanical impedance
121. pyroelectric effect
122. terminal line
123. triboelectric effect
124. transduction element
125. transverse sensitivity
127. thermoelectric transuduction
128. sensitive axis
129. stagnation pressure
131. reference standard
134. operating life
135. storage life
136. life cycling
137. insulation resistance
138. integrating device
139. harmonic distortion
140. harmonic motion
141. ionizing transduction
142. frequency response
143. transfer function
147. impedance matching
148. null type device
151. relative error
155. dynamic response
156. frequency response
157. first-order instrument
158. statistical analysis
159. dead time
160. dead zone
161. input impedance
162. output impedance
164. block diagram
166. common-mode rejection
167. common-mode signal
168. control system
171. differential mode signal
173. frequency response
175. operational amplifier
177. form factor
178. root locus
179. power-density spectrum
180. signal recovery
181. undamped natural frequency
182. virtual earth
183. Laplace transform